President Carter telephoned Canadian Prime Minister Joe Clark yesterday to thank him for Canada's "tremendous exhibition of friendship and support" in smuggling six American diplomats out of Iran last weekend.

In a three-minute conversation Carter, speaking in the presence of reporters in the Oval Office, told Clark:

"I want to thank you and Ambassador [Kenneth] Taylor and the Canadian government and people for the tremendous exhibition of friendship and support and personal and political courage."

Carter added he had been informed that a formal gesture of thanks voted by Congress Wednesday was the first time Congress had taken such an action toward any government.

When Clark expressed concern that Iran might retaliate against the American hostages in Tehran, Carter replied that he didn't believe revelation of the escape by the six who had been hiding in the Canadian Embassy "will be damaging to the well-being of our hostages."

U.S. officials are hopeful that Iranian president-elect Abol Hassan Bani-Sadr wants to end the 80-day impasse over the hostages and, once he has consolidated his power, will begin seeking a way to negotiate their release.

A number of proposals have been put out discreetly by the United States and various intermediaries. Chief among them is a plan for the hostages to be turned over temporarily to an international agency such as the Red Cross while a U.N. commission begins work on investigating Iranian complaints against deposed shah Mohammad Reza Pahlavi.

However, U.S. sources have cautioned that Bani-Sadr needs time to form a government and test his strength within the divided Iranian power structure. As a result, the sources stressed, it could require as much as a month before the Iranians give any clear responses to the new overtures.

In the meantime, the Carter administration still refused yesterday to specify when it will issue regulations formally putting into place the economic sanctions it has threatened to impose against Iran.

Despite official insistance that the administration has not changed its mind about sanctions, there is general belief that they are being delayed as part of the effort to create a concilatory atmosphere for negotiations over the hostages.

gHowever, the Commerce Department said yesterday that it was advised U.S. firms not to sell spare parts to Iranian oil refineries while the hostages remain in custody. The officials said that advisory was given after they learned that an American firm, which was net identified, had received an urgent request for parts from the National Iranian Corp.

The six escapees who were flown back to the United States Wednesday, spent yesterday under tight security in officers' quarters at Dover Air Force Base in Delaware, awaiting the arrival of their families.

Delaware Gov. Pierre S. duPont IV, who spoke to them for 15 minutes, said later they were in "excellent spirits."

He said he had steered away from asking them about "delicate subjects" such as the details of how they got out of Iran. He said their only reference to the 12 weeks they spent hiding in Tehran involved talk of playing "an awful lot of Scrabble and cards."

The six are to appear at a news conference at the State Department today. Department spokesman Hodding Carter appeared at his daily press briefing yesterday wearing a red maple leaf pin in his lapel. He said it was his way of thanking Canada, and, in a reference to today's news conference, he told reporters he would continue wearing the pin until the six "are safely out of your clutches."

In reference to another aspect of the tensions growing out of the situation in Southwest Asia, he said the United States hopes to continue normal relations with the communist countries of Eastern Europe despite the deterioration of U.S. ties with the Soviet Union.

Other department officials said privately that America's West European allies, in discussion's about concerted western responses to Soviet actions in the Persian Gulf area, have stressed the need to differentiate between Moscow and its East European satellites. The United States and the West Europeans are agreed that it is important for the West to keep its lines open to Eastern Europe, these officials added.

In that respect, Hodding Carter noted that the positions of the Eastern European countries on the Soviet intervention in Afghanistan have not been uniform.In particular, Romania, which frequently has been at odds with the Soviets despite its membership in the Moscow-led Warsaw Pact, has gone out of the way to display a chilly attitude toward Soviet actions in Afghanistan.

The White House also announced yesterday a new U.S. pledge of $5.3 million to assist the growing number of Afghan refugees -- in excess of 500,000, according to some estimates -- fleeing into Pakistan.

The new U.S. pledge is in addition to $6.1 million in wheat and other food commodities the administration is making available. It also had said it will earmark for Afghan refugee relief roughly $10 million from a supplemental Food for Peace appropriation now before Congress.